Process of purifying hydrocarbons



March 4, 1 930.

J. C. BLACK PROCESS oF PURIFYING HYDRocARBoNs Filed March l0, 1928 p synthetically Patented Mar. 4, 1930A UNITED STATESy PATENT OFFICE JOHN C. BLACK, OF LOS ANGELES, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO RICHFIELD OIL COMPANY 0F CALIFORNIA, OF LOS ANGELES, CALIFORNIA, A

CORPORATION 0F DELAWARE PROCESS OF IPURIFYING- HYDROCARBONS Application filed. March 10, 1928. Serial No. 260,653.

This invention -relates to the purification of hydrocarbons, and while not necessarily confined thereto, it more specifically refers to the treatment of naphtha or gasoline stock produced bythe cracking of hydrocarbon oils, such as petroleum or shale oil, or distillates derived from relatively high sulphur-bearing crude oils in which hydrogen sulphide, mercaptans and other sulphurbearing hydrocarbons, as Well as varying percentages of unstable hydrocarbons, such as diolefines, may be present, orformed during said distillation or cracking operation.

This invention is particularly vapplicable for refining gasoline stock made according to United States Patent No. 41,426,813 granted to me A ril 22, 1922.

One o the principal objects of this invention is to accomplish a partial desulphurizing and purification of gasoline or naphtha stock by a sequence of operations involving first treating crude gasoline, which may or may not have had a lpreliminary sulphuric acid treatment, with caustic soda, depending upon the quality of the stock to bepuried and the extent of the purification desired, followed by a treatment under pressure with an oxidizing agent in the presence of a water solution of caustic soda, a subsequent treatment with an adsorbent clay at an elevated temperature under pressure, and a final distillation.

Another object of this invention is to provide a continuous system or batch process for purifying gasoline stock produced by cracking petroleum oils to remove therefrom the unstable hydrocarbons either before or after a sweetening operation, or other refining operations known in the art, by a treatment with an adsorbent clay under pressure .and at elevated temperatures sufficient to polymerize all the unstable hydrocarbons contained therein, with the formation of higher boiling oils and then separating the purified gasoline stock from the higher boiling polymerized hydrocarbons, by distillation.

With the foregoing preliminary explanav tion, the preferred embodiment of this invention will now be more fully explained by reference to the accompanying drawing which is4 a diagrammatical representation of an apparatus in which the invention may be carried out.

In the drawing, 1 indicates generally a gasoline supply tank containing the stock to be treated, to which is connected near the top,

connects the mixer 8 to a separator 17. 13

indicates generally a caustic soda supply tank which is connected to the suction side' of a pump 10 by a pipe 11 controlled by the valve 12. A vpipe 14 controlled by the valve 15 is connected to the caustic tank 13 near the top and leadsto a source of supply not shown. A pipe 9 connects the .discharge side of the pump 10 to the bottom of the mixer 8. A pipe 22 connects the separator 17 to heat exchanger 23. A pipe 27 connects the heat exchanger 23 to a heater 26. The heater 26 isprovided with a steam inlet pipe 24 controlled by a valve 25. 31 indicates the steam outletpipe-controlled by the valve 32. The steam supply pipe 24 leads to a source of steam not shown and the steam outlet pipe 31 leads to a source for waste steam not shown. A pipe 28 connects the heater 26 to a mixer 29. 37 indicates generally a supply tank for holding a suspension of manganese dioxide in a water solution of caustic soda. The tank 37 is rovided with a stirrer 38 which is operate byva motor 39 which is connected to the stirrer 38 by means of gears as shown. A pipe 40 controlled by the valve 41 is connected to tank 38 near the top and leads to a source of supply not shown. A pipe 35 controlled by the valve 36 connects supply tank 37 near the bottom to the suction side of pump 34. .A pipe 33 connects the discharge side of pump 34 to the bottom of mixer 29. The mixer 29 may be any mixer known in the art for mixing solutions containing a suspended l 3.0 connects the mixer 29 to a treater 65 ending in a spray line. The pipe 66 connects the treater 65 near the bottom to a separator 67. A pipe 68 connects the separator 67-to the suction slide of a pump 75, the flow from which is controlled by the valve 74. A pipe 69 controlled by the valve 70 connects the separator 67 at the bottom to the spent manganese dioxide caustic soda, tank 71. A pipe 73 controlled; by the valve 72 is connected to the tank 71 near the bottom and leads to a source of storage or recovery plant not shown. A pipe 7 8 controlled by the valve 79 connects the discharge side of pump 75 to clay treater 80. A pipel 83 controlled by the valve 84 connects the pipe 78 to clay separator tank 85. A pipe 76 controlled by the valve 77 connects ythe clay treater 80 at the bottom to the suction side of pumpI 75. A conveyor 81 connects the clay bin 82 to clay mixer'131 at the top Vby means of which desiredainounts of an adsorbent clay may be introduced into the VVsaid clay mixer 131. The pipes 86 and 12.6 controlled 'by valve 127 connect the clay separator 85 to a cooling coil 128. Cooling coil 128 is contained in the cooler box 129. Pipe 130 connects the cooler coil 128 to. the clay mixer131. The clay mixer is provided with a stirrer 132 by means of which the introduced adsorbent agent and introduced gasoline maybe kept in a commingled state. Pipe 134 controlled by valve 133'connects the clay mixer 131 at the bottom to the suction side of ump 135. Pipe 136 controlled by valve 137) connects the discharge side of pump 135 to clay treater 80.

The pipe 86 is connected by a branch p ipe to the suction side of pump 88, the low bein controlled by valve 87. A pipe 89 controlle by the valvef90 connects the discharge side of the pump 88 to heatexchanger 23. A pipe 42 controlled by the valve 43 connects'the heat exchanger 23 to pipe 52. YThe pipe 52 controlled by the valve 53 connects the treated gasoline storage tank 51 to the suction side Aot pump 54. A pipe 44 controlled by the valve 45 connects thelpipe 43 to cooler 46. A pipe 47 controlled by a valve 48 connects the cooler 46 to pipe 91. The pipe 91 controlled by the valve 92 connects t e treatedgasoline tank 51 toa cooler 94. A pipe 49 controlled by a valve 50 is connected to the cooler 46 and leads to a source of cooling water not shown. yA pipe 200 controlled by the valve 201 is connected to the cooler 46 and leads to a source of Iwast not shown. A pipe 55 controlled by' the valve 56 connects the pump 54 on the discharge' side to a heater 59. A pipe 60 controlled by the valve 61 isvconnectedto the Vheater 59 and leads to a source of steam not fractionating tower 64 near the bottom and leads to a source of steam not shown. A pipe 125 connects the fractionating tower 64 at the top to a condenser pipe 104. The condensery pipe 104 is contained in 'the condenser box 105. A pipe 106 connects the condenser pipe 104 to a finished gasoline tank 108. .The valve 107 controls the flow of gasoline coming through the pipe 106.l A pipe 102 controlled by the valve 103 connects the clay separator 85 at the bottom `to the suction side of a pump 101. A pipe 99 controlled by the valve 100 connects the discharge side of pump 101 the valve 202 is connected to the cooler 94.

and leads to a source of waste not shown. The

pipe 91 controlled by the valve 93 connects the'cooler 94 to treated gasoline tank 51. The pipe 113 controlled by the valve 114 connects the. fractionating tower 64 at the bottom to cooler 115. The pipe 121 controlled by valve 122 connects the cooler 115 to a source of'cooling'water not'shown. The pipe 123 controlled by the valve 124 is connected'to the cooler 115 and leads to a source of waste not shown. A pipe 116 controlled by the valve 117 connects the cooler 115 to heavy oil tank 118. The heavy oil tank 118 is provided with an outlet pipe 119 controlled by valve 120. The finished gasoline tank 108 is provided with an outlet pipe 109 controlled by valve 110 and leads to a source of gasoline storage not shown. A pipe 18 controlled by the valve 19 connects the separator tank 17 at the bottom to spent caustic tank 20. The spent caustic tank 20 is provided with an outlet pipe 21 controlled by a valve 22a andaleads to a source of caustic recovery not shown.

The preferred process as carried out in the apparatus just described is as follows:

The crude gasoline storage tank 1 is filled with the stock to be treated from the pipe 2. Thepipe 2, controlled by the valve 3, leads to a source of crude gasoline not shown. Crude gasoline or naphtha stock contained in -the tank 1 Iwhich may or may not have had a preliminary treatment with sulphuric acid, is continuously discharged by th pump 6 into the mixer 8, passing through the pipes 4 and 7, the rate of ow being regulated by operating valve 5. At the same time a regulated stream of awater solution of caustic soda is commingled'with the gasoline stock entering the mixer 8, by operating pump 10.

tion of caustic soda which is commingled with the asoline stock entering the mixer 8 de# pen s upon the stock under treatment. As

e line stock and caustic soda solution passed manganese from the top of the mixer 8 through the pipe 16 and into the separator 17 Where the caustic soda solution containing lsubstantially all of thev hydrogen sulphide in the form of sodium sulphide and a certain portion of the mercaptans 'in solution, are separated from the gasoline stock by regulating valve 19 which permits the separated spent caustic solution to pass through the pipe 18 and into the tank 20. From the separator 17 the caustic treated gasoline stock passes through the heat eXchanger 23 and heater 26 Where a temperature of the desired. degree is attained, preferably 250 to 400 degrees F., this degree of temperature being governed by regulating valve 25 of the entrance steam pipe 24, the exhaust steam passing to a source not shown through the pipe 31, controlled by -the Valve 32. From the heater 26 ythe hot gasoline stock passes through the pipe 28 and into mixer 29 where it is commingled under pressure with a Water solution of caustic soda containing suspended manganese dioxide. The amount of ,caustic soda solution containing suspended manganese dioxide employed in this operation, may range from as 10W as 1 per cent to as high as 10 per cent or a little higher by volume of a6 to 50 degree B. caustic soda water solution, containing 1 to as high as 10 per cent or a little more by Weight, comminuted manganese dioxide. By this treatment with a Water solution of caustic soda containing suspended manganese dioxide, the

mercaptans and any other corrosive sulphurv compounds are converted into non-corrosive compounds, thereby rendering the gasoline stock sweet to the doctor test. By means of the pipe 40 which leadsto a source not shown, controlled by the valve 41, the tank 37 is filled With a Water solution of caustic soda of the desired strength, containing the requisite quantit of manganese dioxide. The ioxide contained in the caustic soda solution in tank 37 is keptin a suspended state by the stirrer 38 which is operated by motor 39. From the tank 37 the caustic soda Water solution vcontaining the suspended manganese dioxide passes through pipe 35 and into the suction side of pump 34 which discharges the same through pipe 33 and into the mixer 29, the rate of flow being governed by valve l36. From the mixer 29 the commingled gasoline .stock and caustic soda solution containing the suspended manganese dioxide, passes t rough treate'r 65, pipe 66 and into separator 67 where the used caustic soda solution and manganese dioxide are separated from the treated gasoline stock and conducted to a tank 71 passing throughthe pipe 69 controlled by the valve 70. 'The spent caustic soda solution containing manganese dioxide is conducted to a recovery plant not vshown passing out through thepipe 73 controlled by the valve 7 2.' The treated gasoline stock now substantially'free of corrosive sulphur compounds and test, passes from separator 67 through the sweet to the doctorpipe 68 and into the suction side of pump 75,

the ow being controlled by valve 74. Pump 75 discharges -the gasoline stock throughv the pipe. 7 8 into the clay treater 80, the flow being regulated by valve 7 9. In clay treater 8O the heated gasoline stock under its own vapor pressure, which is approximately 100 to 300 pounds, and at a temperature ranging from 200 to 400 degrees F., is commingled with the required amount of an adsorbent agent such as a comminuted h drous magnesium silicate, an aluminum s1 icate, or an acid treated clay, the latter of which may be pro duced according to the method employed in my United States Patent 1,656,997, Process of refining oil, patented January 24, 1928. The amount of adsorbent agent employed ranges from 1/2 of one per cent to as high as 10 per cent by Weight, depending upon the stock tobe treated and the product desired. The adsorbent agent not only adsorbs certain impurities from the gasoline stock, but

also acts as a polymerizing agent, thereby effecting a relatively rapid polymerization of the unstable hydrocarbons such as the diolefines, and other unstable hydrocarbons which if allowed to remain in the gasoline stock on lstanding in storage, would slowly condense with the formation of undesired gasoline' soluble coloredsconstituents, the removal of which would be necessary in order to obtain a Water white gasoline stock, thereby incurrin an additional expense and loss of the gaso ine stock. The clay treater is so arranged that a circulating agit-ation may be eiiected, and the gasoline stock continuously commin 'led with clay and continuously withdrawn 1nto the clay separator 85.

This is accomplished by proper regulation of valves 77, 84, 79 and 7 4. A comminuted adsorbent agent, contained in the hopper 82, is continuously introduced into the clay mixer 131 by operation of the elevator 81. At the same time a small quantity of the treated gasoline or naphtha from the clay separator 85 is continuously introduced into the clay mixer 131 and commingled with the introduced adsorbent agent by the operation of stirrer 132. The quantity of treated gasoline or naphtha introduced is just sufficient to obtain a pumpable mixture. The gasoline introduced into clay treater 131 from clay separator 85 passes through the pipes 86 and' 126, .Y cooling coil 128 and pipe 130. The gasoline is cooled below its vaporizing temperature during the passage through cooling coil 128.

' From the clay mixer 131 the commingled adsorbent agent and gasoline passes through \`the pipe 134, controlled by valve 133, and

into the suction side of pump 135 which discharges the same through the pipe 136, conytrolled by the valve 137 and vinto the clay treater 80. y

. The commingled gasoline stock and adsorbent agent in clay treater 80 is continuously discharged Ithrough the pipe 83 and into the clay separator 85 by regulating valve 84. In the clay separator 85 the adsorbent agent separates from the gasoline stockand' is drawn off together witha small percentage of the gasoline 'stock passing through the pipe 102, the flow of which is regulated'by valve 103. From the pipe 102, the adsorbent agent containing a small percentage lof the gasolinestock passes into the suction'side of pump 101 which discharges the same through the'pipe 99, controlled by the valve 100 and into the filter press 97, Where he major portion of the gasoline stock contained `by the adsorbent agent is separated, the adsorbent agent collecting on the, filter plates 98 and the gasoline stock passing through the 4pipe 95, controlled by the valve 96. From the pipe 95 the separated gasoline stock passes through the cooler 94 which is provided with a water inlet pipe 205 controlled by valve 204 and a water outlet pipe 203 controlled by valve 202, by means of which the separated gasoline stock is cooled to the desired degree.- From the cooler 94, the cool gasoline stock separated from the agent passes through the pipe 91 controlled by the valve 92 and into the storage tank 51.

The treated gasoline stock as it separates from the adsorbent agent inl clay treater 85 passes through pipe 86 and into the suction side of pump 88, the flow of which is controlled by valve 87. The pum 88 discharges the hot treated gasoline stoc through the .-'pipe 89, controlled by the valve 90, and

through ythe heat exchanger 23 where the said hot treated gasoline stock undergoes a heat,

exchanc e with the incoming oil tov be treated. From t e heat exchanger 23 theip'artly coaled gasoline stock passes through pipe 42 and into the suction side of pump 54, or the partly cooled gasoline stock may be caused to pass through the cooler 46 and then into the storage tank 51 in which case valve 43 is,l closed, and valve 45 is open, permitting the`treated stock to pass through pipe 44, cooler 46, pipe 47 and into pipe 91 which is connected to storage tank 51, valve 48 being open. The pump 54 discharges the treated gasoline stock coming from the storage tank 51 through the pipe 55, controlled by the valve 56, or the treated gasoline stock coming through thepipe 42 may be directly introduced into thesuction side of pump 54without passing through the cooler 46 and thereafter discharged through the pipe A55 and into the heater 59. Preferably thepartly cooled gasoline stock is not passed through the cooler 46 but is directly permittedrto How into the suction side of the `pump 54 whereby conservation of heat is effected in the distillation operation to follow.

The gasoline stock. passes from the pipe 55 through the heater 59, pipe 57 and 'into the fractionating tower 64 where the gasolineboiling point stock 'is separated from the higher boiling hydrocarbons and polymerized products produced in the treatment. In

order to facilitate the distillation operation.

steam is introduced into the fractionating tower 64 coming froma source not Ishown through the pipe 111 controlled bythe valve 112. The vaporized purified gasoline stock and introduced steam pass from the fraction' ating tower 64 through the pipe 125 and are condensed during the passage through the condenser coil 104.` The condensed uriiied v gasoline stock andl water pass from t ye con.

denser coil 104 through the pipe 106 and into the finished gasoline tank 108;, the iow being regulated by valvev 107. The finished gaso line tank 108 is provided with pipe 109 controlled by valve 110 which ,leads to a storage tank not shown.

While the foregoing described processis well adapted for 'carrying out the objects of the present invention, it is to be understood that various other oxidizing agents known in the art may be employed in place of manganese dioxide for rendering gasoline sweet to the doctor test, such as hypochlorite of soda, copper oxide, iron oxide, per-sulphate's, and the like, and thereafter treated with an adsorbent agent of the class described at temperatures'and pressure sufficient to poly# meriz'e the unstable unsaturated hydrocarbons by the method herein described and thereafter separated from the treated gasoline or 'naphtha stock by fractionation. Also it is to be understood thatthe crude gasoline or na htha stock may be first treated with an adsorbent agent atthe temperatures and pressures described in the preferred process and thereafter treated with sulphuric acid, caustic soda, and an oxidizing agent to render the gasoline or naphtha stock sweet to the doctor test or by other processes Well known in the art, and that various other cha vges and modifications may be made without departing from the spirit of the invention and the inf vention includes all such changes and modifications las appear Within the scope of the ap ended claims. x

, at I'claim is:l

1. A process of treating gasoline or naphtha derived from cracking petroleum oils, comprising commingling the gasoline or naphtha stock which has been treated with sulphuric acid, caustic soda and rendered` y sweet to the doctor test by treatment with a water solution of caustic soda containing the requisite quantity of suspended manganese dioxide, with a comminuted adsorbent clay at an elevated temperature suiiicient to 10,polymerize substantially all the unstable hydrocarbons contained therein and un'der a pressure suiiicient to prevent any substantiall .vaporization of the gasoline or naphtha and then separating the gasoline or naphtha from 1 5 `the products of polymerization, by distillation. t 2. A process of treating gasoline or naphtha derived from cracking petroleum oils comprising, continuously commingling the gasoline or naphtha with a water solution of --caustic soda, continuously separating the water solution of caustic soda containing dissolved impurities from the gasoline or naphthe unstable hydrocarbons contained therein, and iinally separating the urilied gasoline or naphtha from higher boiling oils and products of polymerization.

In testimony whereof I affix my signature.

JOHN C. BLACK.

tha, continuously passing the caustic treated i '25 gasoline or naphtha in heat exchange relationship with hot gasoline or naphtha subsequently produced, and further heatingthe said caustic treated gasoline or na htha to a tem erature of substantially notv ess than 30 250 egrees .F., continuously commingling the said heated gasoline or naphtha with a water solution of caustic soda containing suspended manganese dioxide in quantities sufcient to render the gasoline or na htha sweet to the doctor test, continuous y separating the heated gasoline or naphtha from the water solution of caustic soda and suspended. manganese dioxide, continuously commingling the .said separated heated gasoline or naphtha with a comminuted adsorbent clay at a pressure suicient to prevent any substantial vaporization of the gasoline or naphtha for a period of time suiiicient to polymerize' substantially all of the unstable hydrocarbons contained therein, and then separating the puriiied gasoline or naphtha from the. higher boiling'oils and products of polymerization, by distillation.

3. A process of treating gasoline or naph- `tha derived from cracking petroleum oil comprising, commingling the gasoline` or naphtha with a water solution of caustic soda contain-A ing suspended manganese dioxide at an elevated temperature and for a period of time suiiicient to render the gasoline sweet to the doctor test, separating the gasoline or naphtha from the Water solution lof caustic soda and suspended manganese dioxide and then commingling the separated gasoline yor naphtha with a comminuted adsorbent clay at a temperature of substantially not less than 250 degrees F., under a pressure sufficient to prevent vaporization of the gasoline or naph' tha and for a period of time suiiicient to eff feet polymerization of substantially `all of 

